Although the loading position of the starter in an engine compartment is usually a place close to and beside the engine, functional components with a higher priority for the engine performance, such as an intake manifold, are arranged around the engine in many cases.
For this reason, the outer diameter size of the starter used only for starting the engine is often restricted. Therefore, in order to secure the market competitiveness of the product itself, improving an ease of arrangement of the starter by miniaturization is important.
On the other hand, adoption of an idle stop system is predicted to increase from now on for the improvement in fuel consumption resulting from a global warming issue.
However, since the number of times of starting engines will increase rapidly if the idle stop system is adopted, therefore, durability of the starter, the improvement in reliability over a long period of time, and reduction of operation sound are needed.
Here, in durability, the improvement in durability of a pinion and a ring gear is an important subject.
For improving durability, a method of engaging the pinion with the ring gear needs to be improved, and one way of achieving this is to ensure the timing of pushing out the pinion and energizing a motor is accurate.
As conventional technology realizable that improves the above-mentioned ease of arrangement and durability is well known in Japanese Patent Publication No. 2009-191843.
JP 2009-191843 discloses an electromagnetic switch device that has a solenoid for pinion extrusion that extrudes the starter's pinion to the engine side and a solenoid for motor energization that opens and closes a main switch provided in a motor circuit of the starter, and operations of the both solenoids can be controlled independently.
By the way, if the spread of idle stop systems, i.e. to make them become more popular, is taken into consideration, the cost also becomes an important subject. Especially, when replacing the conventional starters to the starters for idle stop system, the starters are replaced one by one for every area and a type of a car.
In the meantime, it is necessary to produce conventional starters and starters for idle stop systems in parallel and this situation is expected to continue for a considerably long period of time, thus the cost including this period must be considered.
As a cost reduction measure in this case, common parts usage is mentioned as an important means. However, the electromagnetic switch device disclosed in the above-mentioned JP 2 009-191843 h as a large effect on the ease of arrangement, a subject in respect of the common parts usage with the electromagnetic switch used for the conventional starter.
That is, although the solenoid for pinion extrusion disclosed in JP 2 009-191843 can share coils, plungers, etc. with the parts used for the electromagnetic switch of conventional starters, many parts cannot be shared for the solenoid for motor energization.